/Engine/Source/Runtime/SlateCore/Public/Input/Reply.h
the Content that we should use for the Drag and Drop operation; Invalid SharedPtr if a drag and drop operation is not requested
const [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FDragDropOperation](API\Runtime\SlateCore\Input\FDragDropOperation) > & GetDragDropContent() const